Ivan is using his desk setup mainly for work. Ivan is a freelance illustrator and graphic designer who creates very large digital paintings at high resolutions, which requires a lot of hardware horsepowers and a good display to view them.
Ivan recently upgraded to 27" iMac 2019 with 64 GB of ram and a core i9 CPU. He wanted to use his iMac with the two 1080p monitors he had been using previously while retaining as much desk space as possible.
Ivan uses Astropad Studio on any iPad Pro 2018 as his graphics tablet so that he can mirror his iMac display and paint directly on the screen. He can even go wireless on his porch with a 6ms response time, which is almost imperceptible.
The most challenging part for Ivan was figuring out how to manage the storage at a decent price. He wanted an all SSD setup, but he didn't want to pay Apple's prices. He ended up getting 2TB internal SSD and an enclosure to connect over USB. Now, he has a system and software running off of the internal 128 GB of flash storage, and all of his files running off of the SSD. This was very important for him since his work files are often in multiple gigabytes.
Ivan's advice, if you want a three monitors setup, having 1080p for second and third displays are fine. He had no problem using extra monitors with lower resolution since his work is done mostly on the 5K display and he spends 90% of the time staring at it. His secondary displays are usually for Spotify, Messages, Email, and reference photos.